Endothelial dysfunction in rectal cancer patients chronically exposed to ionizing radiation.

We sought to identify the features of endothelial function in rectal cancer patients who were exposed to chronic ionizing radiation from a nuclear test site in Kazakhstan. We examined 146 individuals, 76 of whom were rectal cancer patients. The existence of a complex of disturbances of the endothelium and hemostasis systems in patients vs non-patients was revealed. Endothelial dysfunction was expressed as an increase of nitric oxide (NO) production along with decreases in vasodilatation function, and increased levels of von Willebrand factor in blood, along with an increase in the number of circulating endotheliocytes. Significant correlations between indicators of endothelial function and vascular-platelet hemostasis were observed. These changes and their interrelations were expressed more strongly in the patients who lived in the contaminated area around the nuclear test site. Such patients could have an increased risk of thrombosis and other complications after the treatment of a malignant neoplasm.